x86: add pci=check_enable_amd_mmconf and dmi check

so will disable that feature by default, and only enable that via
pci=check_enable_amd_mmconf or for system match with dmi table.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/x86/kernel/mmconf-fam10h_64.c b/arch/x86/kernel/mmconf-fam10h_64.c
index 37897920ec6..edc5fbfe85c 100644
--- a/arch/x86/kernel/mmconf-fam10h_64.c
+++ b/arch/x86/kernel/mmconf-fam10h_64.c
@@ -6,12 +6,15 @@
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/pci.h>
+#include <linux/dmi.h>
 #include <asm/pci-direct.h>
 #include <linux/sort.h>
 #include <asm/io.h>
 #include <asm/msr.h>
 #include <asm/acpi.h>
 
+#include "../pci/pci.h"
+
 struct pci_hostbridge_probe {
 	u32 bus;
 	u32 slot;
@@ -176,6 +179,9 @@ void __cpuinit fam10h_check_enable_mmcfg(void)
 	u64 val;
 	u32 address;
 
+	if (!(pci_probe & PCI_CHECK_ENABLE_AMD_MMCONF))
+		return;
+
 	address = MSR_FAM10H_MMIO_CONF_BASE;
 	rdmsrl(address, val);
 
@@ -213,3 +219,25 @@ void __cpuinit fam10h_check_enable_mmcfg(void)
 	       FAM10H_MMIO_CONF_ENABLE;
 	wrmsrl(address, val);
 }
+
+static int __devinit set_check_enable_amd_mmconf(const struct dmi_system_id *d)
+{
+        pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
+        return 0;
+}
+
+static struct dmi_system_id __devinitdata mmconf_dmi_table[] = {
+        {
+                .callback = set_check_enable_amd_mmconf,
+                .ident = "Sun Microsystems Machine",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Sun Microsystems"),
+                },
+        },
+	{}
+};
+
+void __init check_enable_amd_mmconf_dmi(void)
+{
+	dmi_check_system(mmconf_dmi_table);
+}